/*--- insert.c ---------------------------- Listing 5-5 ---------
 * Insertion sort of an array
 *
 * #define DRIVER to compile a test driver
 * Driver must be linked to sortsub.c (Listing 5-1)
 *-------------------------------------------------------------*/

#include "sorthdr.h"

void InsertionSort(Element **Array, int N, CompFunc Compare)
{
    int step;

    /* Look at 2nd thru Nth elements, putting each in place */
    for (step = 1; step < N; step++) {
        int i;
        Element *temp;

        /* Now, look to the left and find our spot */
        temp = Array[step];
        for (i = step - 1; i >= 0; i--) {
            if (Compare(Array[i], temp) > 0) {
                /* Not there yet, so make room */
                Array[i+1] = Array[i];
            } else /* Found it! */
                break;
        }
		
        /* Now insert original value from Array[step] */
        Array[i + 1] = temp;
    }
}

#ifdef DRIVER
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include "sortsub.h"

/*
 * A comparison function
 */
int Cfunc(Element *L, Element *R)
{
    return (strncmp(L->text, R->text, 5));
}

void main(int argc, char *argv[])
{
    Element **Array;
    int Items = 2000;

    if (argc != 2 && argc != 3) {
        fprintf(stderr, "Usage: insert infile [maxitems]\n");
        return;
    }

    if (argc == 3)
        Items = atoi(argv[2]);

    if ((Items = LoadArray(argv[1], Items, &Array)) == -1)
        return; /* Couldn't load file */

    InsertionSort(Array, Items, (CompFunc)Cfunc);
    ShowArray(Array, Items, (CompFunc)Cfunc);
}
#endif
